1. Field of the Invention
The present invention relates to a real-time infrared chemical imaging spectroscopic apparatus, and more particularly to a real-time infrared chemical imaging spectroscopic apparatus for analysis of chemical composition of a microstructure in a non-contact and non-destructive manner.
2. Description of Related Art
Infrared absorption spectrum is one of the methods for analyzing the chemical composition of a material. With the introduction of Fourier transformation technology, the infrared absorption spectrum has been widely applied for analyzing molecular properties and quantities. Even so, both the conventional infrared absorption spectrometer and the Fourier-transform infrared one require sophisticated computation and to be time-consuming to obtain the infrared absorption spectral of a sample.
An example is made with reference to the commercial Fourier-transform infrared spectrometer. A beam of radiation from a source is collimated and impinges on a beam splitter, which transmits approximately half of the radiation and reflects the other half. The resulting twin beams are then reflected from mirrors, one of which is fixed and the other of which is movable. The beams then meet again at the beam splitter, which half of each beam directed toward the sample and detector. The two beams travel in different path length form mirrors and recombine on the beam splitter, then passing through sample together and directed to a detector. In this connection, a time-domain spectra is concerned with changes in radiation power with time has to go through the complex fast Fourier transform (FFT) to obtain a frequency-domain spectra within the information of chemical composition of sample. As such, the sophisticated computation is not only time-consuming but also requires hardware or software in cooperation with signals from a Michelson interferometer. Hence, this spectrometer is complex, excessively large and costly.